Pallet lever for clockwork mechanisms



- Feb. 13, 1940. I H. JUNGHANS 2,190,156

PALLET LEVER FOR CLOCKWORK MECHANISMS Filed June 9, 1937 I71 V8 7223/; He ZmuZ Jurzyflaw:

Patented Feb. 13, 1940 UNITED STATES PATENT oFFIcE PALLET LEVER FOR GLOCKWORK MECHANISMS In Germany 2 Claims.

This invention relates to pallet levers for clockwork mechanisms, and more particularly for clocks of large size.

In these levers the pallets themselves consist 5 of steel, whilst the body of the lever is also made of steel or of brass. The working up of these parts of the levers is, however, comparatively difficult and requires some considerable time, as they must naturally be worked very accurately.

To avoid this tedious treatment it is proposed in accordance with the invention to employ levers which are produced by a pressure casting process or in a pressing operation. In this manner the production is greatly simplified, and generally speaking a subsequent treatment will not be required. There may be employed metal alloys or also other substances, such as synthetic resin substances, which are capable of being cast by pressure or also pressed.

The attachment of the pallets in the lever members thus produced may then take place by means of screws, or it is also possible to introduce the pallets into the mould upon the pressure casting process and thus to cast them into the body of the lever. The pallets may be secured to the lever immediately also when pressing the body of the lever, so that also in this case time and expense can be saved by the elimination of separate assembly and adjustment.

Particularly when producing these levers from synthetic resins there is obtained the additional advantage that the entire lever is lighter than a metallic lever, so that the spindles are subjected to a smaller load and in consequence, in similar fashion to the bearings, enjoy a longer life.

Certain embodiments of the invention are illustrated by way of example in the accompanying drawing.

Fig. l is a plan view of a. pallet lever, in which the attachment of the pallets-different at the two ends-is performed by means of screws which are screwed in parallel to the axis of rotation of the lever.

Fig. 2 is a front el Figs. 3 and i are which the attachment their axes extending in the arms of the lever.

The body a of the lever is produced in all cases in a pressure casting or pressing operation from metal alloys or synthetic resins and given a substantially square cross section as seen from the drawing.

In the first embodiment (Figs. 1 and 2 at the ovation of Fig. 1.

similar views of a lever in screws are located with longitudinal direction of April 25, 1936 right) the pallet b' preferably curved in the plane of oscillation is introduced into a slot in the body a, which slot is open at the bottom. It is held in the slot by a plate 11, which bears against the underside of the pallet and is held by screws 0, which are screwed into the lever parallel to the axis of rotation thereof.

In the second embodiment (Figs. 1 and 2 at the left) the pallet b is also situated in an open slot in the lever body a, but is held merely by the correspondingly large head e of a screw which is likewise screwed into the lever a parallel to the axis of rotation thereof.

In the third embodiment (Figs. 3 and 4:) the pallets are introduced into closed slots in the lever a. The attachment screws 1 are in this case screwed into the ends of the lever a at right angles to the axis of rotation and with their axes extending in the longitudinal direction of the lever arms.

As shown in the drawing, the pallets b are arcshaped curved in the plane of oscillation and fit into slots of similar curvature in the lever body a. The pallets are preferably of non-linear or curved shape, and may advantageously be placed in the die or mould prior to the casting or press ing operation and may be cast or molded into the lever body a during its formation.

Since these pallet levers or anchors are intended for use mainly in large size clocks, it is important to give the levers considerable thickness, as seen in the figures, to produce great rigidity and stiffness. It would therefore not do to produce them in the usual manner from sheet metal on thin pressed or rolled plate, which can easily bend. Accordingly levers of substantially square cross section formed by pressure casting, in accordance with the present invention, are best suitable for large clock mechanisms.

As already stated, the attachment with the assistance of screws may be omitted entirely if the pallets b are introduced into the mould immediately upon the pressure casting or pressing of the lever a and are accordingly united with the lever during the production of the latter it- 45 self.

If desired, however, additional screws may also be screwed in in the one or other fashion as an extra precaution. As seen in Figs 3 and 4 the top and bottom surfaces of the lever a are 50 perfectly flush or plain with no projections, the pallets 2: instead projecting through the side faces of said lever.

It will be understood that no limitation is made to the specific embodiments illustrated in 55 the drawing, and that numerous modifications are quite possible within the meaning of the above description and the annexed claims without departing from the spirit of the invention.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is:

1. A pallet lever for largeclockworkscomprising a two-armed non-flexible lever body, a slot being provided near the end of each arm, a pallet fitting in each of said slots, and. a clamping screw threaded at the end of each arm in the longitu- 

